A050578 Numbers n such that 105*2^n-1 is prime.

2, 3, 5, 6, 8, 9, 25, 32, 65, 113, 119, 155, 177, 299, 335, 426, 462, 617, 896, 1377, 1847, 2495, 2810, 3743, 3884, 3897, 5235, 6418, 6550, 8066, 8757, 9518, 11610, 16542, 17485, 17984, 18530, 18885, 25017, 26642, 30366, 40470, 45770, 56903, 57819, 66077, 69958, 75569, 92357, 108867, 145422, 201556, 262670, 280022, 472430, 484658, 530360, 801978, 814850

Offset

1,1

Links

Table of n, a(n) for n=1..59.

Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300

Wilfrid Keller, List of primes k.2^n - 1 for k < 300

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

Kosmaj, Riesel list k<300.

Prog

(PARI) is(n)=ispseudoprime(105*2^n-1) \\ Charles R Greathouse IV, Jun 13 2017

Crossrefs

Sequence in context: A364807 A294941 A028374 * A283513 A028776 A028734

Adjacent sequences: A050575 A050576 A050577 * A050579 A050580 A050581

Keyword

hard,nonn

Author

N. J. A. Sloane, Dec 29 1999

Extensions

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008

Status

approved